WordPress - Widget - Select a post of CPT

    // http://www.wpbeginner.com/wp-tutorials/how-to-create-a-custom-wordpress-widget/
    // 
    // Select a Restaurant
    class eoc_widget_select_restaurant extends WP_Widget {

        function __construct() {
            parent::__construct(
                // Base ID of your widget
                'eoc_widget_select_restaurant', 

                // Widget name will appear in UI
                __('Select a Restaurant', 'eatoutcornwall'), 

                // Widget description
                array( 'description' => __( 'Widget to select a Restuarant', 'eatoutcornwall' ), ) 
            );
        }

        // Creating widget front-end
        // This is where the action happens
        public function widget( $args, $instance ) {
            $title      = apply_filters( 'widget_title', $instance['title'] );
            $number     = apply_filters( 'widget_number', $instance['number'] );
           
            if ( (! empty( $title ) ) && (strlen($number) != 0) ) {

                // before and after widget arguments are defined by themes
                echo $args['before_widget'];

                    echo "<div class='widget-select-restaurant clear'>";

                            echo $args['before_title'] . $title . $args['after_title'];

                            $query_args = array(
                                'post_type'                 => 'restaurants',
                                'p'                         => $number
                            );

                            // The query
                            $child_query = new WP_Query($query_args);

                            // The loop
                            if( $child_query->have_posts() ) : while ( $child_query->have_posts() ) : $child_query->the_post(); ?>

                                <!-- article -->
                                <article id="post-<?php the_ID(); ?>" class="clear" itemscope="" itemtype="http://schema.org/Restaurant">

                                    <?php
                                        echo "
                                                <div class='thumbnail'>
                                                    
                                                    <img src='".get_the_post_thumbnail_url( get_the_id(), 'eoc-thumbnail-300-200' )."' alt='".get_the_title()."' itemprop='image'>";

                                                    echo "<div class='textwidget'>
                                                            
                                                            <h4>
                                                                <a href='".get_the_permalink()."' title='".get_the_title()."'>
                                                                    <span itemprop='name'>"
                                                                        .get_the_title().
                                                                    "</span>
                                                                </a>
                                                            </h4>";

                                                            echo "
                                                            <span itemprop='address' itemscope='' itemtype='http://schema.org/PostalAddress'>
                                                                <span class='town' itemprop='addressLocality'>".get_field('business_town', get_the_id())."</span>
                                                            </span>
                                                            <span class='telephone' itemprop='telephone'>Tel: ".click_telephone( get_field('business_telephone', get_the_id()) )."</span>";

                                                            

                                        echo "          </div>

                                                </div>";

                                    ?>

                                </article>
                                <!-- /article -->

                            <?php endwhile; endif;

                    echo "</div>";

                echo $args['after_widget'];

            }

            wp_reset_postdata();

        }

        // Widget Backend 
        public function form( $instance ) {
           
            if ( isset( $instance[ 'title' ] ) ) {
                $title = $instance[ 'title' ];
            } else {
                $title = __( '', 'eatoutcornwall' );
            }
           
            if ( isset( $instance[ 'number' ] ) ) {
                $number = $instance[ 'number' ];
            } else {
                $number = __( '', 'eatoutcornwall' );
            }

            // Widget admin form
            ?>
            <p>
                <label for="<?php echo $this->get_field_id( 'title' ); ?>"><?php _e( 'Title:' ); ?></label> 
                <input class="widefat" id="<?php echo $this->get_field_id( 'title' ); ?>" name="<?php echo $this->get_field_name( 'title' ); ?>" type="text" value="<?php echo esc_attr( $title ); ?>" />
            </p>


            <p>
                <?php

                    $query_args = array(
                        'post_type'                 => 'restaurants',
                        'posts_per_page'            => -1,
                        'post_status'               => 'publish',
                        'orderby'                   => 'title',
                        'order'                     => 'ASC',
                        'meta_key'                  => 'business_paid_listing',
                        'meta_value'                => true
                    );

                    // The query
                    $child_query = new WP_Query($query_args);

                    echo '<select name="'.$this->get_field_name( 'number' ).'">';

                            if( $child_query->post_count === 0 ) {

                                echo '<option value="0">No PAID Restaurants</option>';

                            } else {
                                echo '<option value="0">Select Restaurant</option>';
                            
                                // The loop
                                if( $child_query->have_posts() ) : while ( $child_query->have_posts() ) : $child_query->the_post();

                                    echo '<option value="'.get_the_id().'" ';

                                        if( $number == get_the_id() ) {
                                            echo 'selected';
                                        }

                                    echo '>'.get_the_title().'</option>';

                                endwhile; endif;

                            }

                    echo "</select>";

                    wp_reset_postdata();

                ?>
            </p>

            <?php 
        }
        
        // Updating widget replacing old instances with new
        public function update( $new_instance, $old_instance ) {
            $instance = array();
            $instance['title'] = ( ! empty( $new_instance['title'] ) ) ? strip_tags( $new_instance['title'] ) : '';
            $instance['number'] = ( ! empty( $new_instance['number'] ) ) ? strip_tags( $new_instance['number'] ) : '';
            return $instance;
        }
    } // Class celtic_widget_posts ends here

    // Register and load the widget
    function wpb_load_widget_restaurant() {
        register_widget( 'eoc_widget_select_restaurant' );
    }
    add_action( 'widgets_init', 'wpb_load_widget_restaurant' );
    // Select a Restaurant